System and method for using a capsule device

ABSTRACT

The present invention discloses a method to move a magnetic capsule linearly both horizontally and linearly in a very controllable fashion, wherein the direction of a combined external magnetic field, the force experienced by the magnetic capsule, the movement direction of the capsule and magnetic direction of the magnetic capsule can be all aligned in parallel to each other.

TECHNICAL FIELD OF THE DISCLOSURE

This patent application relates to the art of capsule devices to be usedin medical related applications, and more particularly, to systems touse two external magnetic generating means to navigate a magneticcapsule through a patient's GI track and methods of using the same.

BACKGROUND OF THE DISCLOSURE

The magnetic controllable capsule endoscope has been widely usedcommercially in the stomach examination and proved to be verysuccessful. However, the same magnetically controlled capsule endoscopeis not currently used to be placed inside the small bowl and colon toperform a routine examination.

To date, there are three types of external magnetic field generationsystems to guide magnetic capsule endoscope devices while traveling in apatient's GI track. They are electromagnetic coils, electromagnet andpermanent magnet. In order to meet the requirement of providingsufficient driving force, by external magnetic field or externalmagnetic gradient to move a typical magnetic capsule endoscopethroughout a patient's small bowel, the power consumption forelectromagnetic coils and electromagnet systems is very large, and theheat dissipation can make these systems even more bulkier and eventuallyvery expensive to build and operate. Additionally, for electromagneticcoils and electromagnet systems, the electromagnetic compatibility (EMC)is also a big challenge, and potential safety issue relating to theelectromagnetic field also post some concern.

Comparing to electromagnetic coils, the permanent magnet is a much moreclean and efficient way to generate large magnetic field or fieldgradient. However, the control algorithm of the permanent magnet is muchmore complex than the electromagnetic coils. The electromagnet has alittle bit more flexibility then the permanent magnet, since itsstrength can be adjusted by the current. However, for the control of themovement of the magnetic capsule, the electromagnet has the same orderof the complexity of the permanent magnetic field. And to achieve thesame magnetic field or field gradient, the electromagnet will occupy 2-3times larger space than the permanent magnet. As for the permanentmagnet, the sphere shape is the most efficient for the remote field orfield gradient generation.

Therefore, magnetic control system to navigate a capsule through a smallbowel is needed, the said system should employ an external permanentmagnet dipole and easy to use.

SUMMARY OF THE INVENTION

The present invention discloses a system and method that can be used toexamine a patient's GI track.

One technical problem solved by the present invention, is a magneticcapsule can be suspended in a target location without any physicalsupport such as being supported by the wall, hanging from the top, orsuspended in a liquid.

Another technical problem solved by the present invention, is that amagnetic capsule can move linearly both horizontally and linearly in avery controllable fashion, without any erratic movement.

Another technical problem solved by the present invention, is that amagnetic capsule can adjust orientation without being supported anddegree of the adjustment is between 0-45 degrees.

Another technical problem solved by the present invention, is that amagnetic capsule can rotate smoothly, either vertical spin or planarrotation.

Another technical problem solved by the present invention, is that anoverall movement of the capsule is contributed by two magnetic balls andtwo magnetic ball can work individually and coherently.

Another technical problem solved by the present invention, is that theoverall movement of the capsule is contributed by two magnetic balls butat certain position or orientations of the magnetic capsule, onemagnetic ball is a major movement contributor and the other magneticball is minor movement contributor, but at other positions ororientations, the two magnetic ball contributes equally to the movementof the magnetic capsule.

One advantage of the present invention, is that movement speed of thecapsule can be adjusted in two independent ways, including movement ofthe magnetic balls in a certain movement direction and also undercombined magnetic field strength.

On one hand, the present invention provides a variety of combinations ofmovement of the magnetic capsule, which are not possible before. On theother hand, the present invention provides a capsule to move within aconfined area with defined route in a very controllable and tranquilmanner.

Another advantage of the present invention is that the magnetic capsulecan navigate make a smooth left turn and right turn along a colonchannel. The magnetic capsule can turn from 0-360 degrees continuously.

In the scope of the present invention, the magnetic capsule can movelinearly, including both horizontally and vertically, and the magneticcapsule can rotation and spin between 0-360 degrees continuously whilemaintaining its original position, and the orientation of the capsulecan be adjusted accurately. By the combination of the horizontal andvertical rotation, the capsule can be orientated to any direction.

In one aspect of the present invention, a method for controllingmovement of a magnetic capsule in a target area, is described. Themethod comprises

introducing a magnetic capsule into a target area, said magnetic capsulehas a longitude direction and the magnetic dipole placed inside themagnetic capsule has a magnetization direction coincide with thelongitude direction of the magnetic capsule;

providing an external magnetic control system comprising more than onemagnetic generation means;

moving the external magnetic control system to a first position with afirst orientation, configured to move the magnetic capsule in a firstmovement direction, wherein the first movement direction coincide withthe longitude direction of the magnetic capsule.generating a combined external magnetic field configured to deliver aforce to the capsule in the longitude direction of the magnetic capsule.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the disclosure will be more clearly understoodfrom the following detailed description taken in conjunction with theaccompanying drawings in which:

FIG. 1 shows a schematic illustration of a magnetic capsule system inaccordance with aspect of the present invention;

FIG. 2 shows a perspective view of an exemplar external magnetic controlsystem in accordance with aspects of the present invention; wherein thebed is extended outside of the supporting frames;

FIG. 3 shows a perspective view of an exemplar system in accordance withaspects of the present invention; wherein the bed is placed inside ofthe supporting frames;

FIG. 4 shows an exploded perspective view of an exemplar system inaccordance with aspects of the present invention; wherein the bed isplaced inside of the supporting frames and assemblies are not placedtogether to better illustrate the system structure;

FIG. 5 shows an exploded perspective view of an exemplar system inaccordance with aspects of the present invention, wherein the platformor bed is removed so that the structural components can be clearlydisplayed and labeled;

FIG. 6 is a cross sectional view of the external magnetic system, whenviewing from the back of the external magnetic control system;

FIG. 7 is a left side view of the system of FIG. 6;

FIG. 8 is a top view of the system of FIG. 6;

FIG. 9 is an illustration of a magnetic capsule in the accordance withthe aspect of the present invention;

FIG. 10 is a schematic diagram to illustrate that capsule can movehorizontally along an XY plane, wherein the capsule magnetizationdirection is the same as the forward movement direction;

FIG. 11 is a schematic diagram to illustrate that a capsule can movevertically away from the XY plane in the z direction, wherein thecapsule magnetization direction is the opposite to the forward movementdirection;

FIG. 12 is a force and magnetic field relative distribution chart whenthe positions of the two magnets and magnetic capsule are as listed inFIG. 11;

FIG. 13 is a schematic illustration of another operation conditionwherein the magnetizations of the two magnets are opposite to the magnetcapsule;

FIG. 14 is a force and magnetic field relative distribution chart whenthe positions of the two magnets and magnetic capsule are as listed inFIG. 13;

FIG. 15 is schematic illustration of another operation condition whereintwo magnetic balls are aligned vertically; their magnetizations of bothballs are same and the magnetization directions are mirror image to eachother along the middle plane between them;

FIG. 16 is schematic illustration of another operation condition whereintwo magnetic balls are aligned vertically, their magnetizations of bothballs are same and the magnetization directions are mirror image to eachother along the middle plane between them, and wherein the magneticcapsule is dragged forward;

FIG. 17 is schematic illustration of another operation condition whereintwo magnetic balls are aligned vertically, their magnetizations of bothballs are same and the magnetization directions are mirror image to eachother along the middle plane between them, and wherein the magneticcapsule is dragged forward;

FIG. 18a and FIG. 18b illustrate initial position and orientation of themagnetic capsule and external magnetic balls in a process to change amagnetic capsule through the adjustment in the external magnetic system;

FIG. 19 is a finished position and orientation of the magnetic capsuleand external magnetic balls in a process to change a magnetic capsulethrough the adjustment in the external magnetic system;

FIG. 20 is another finished position and orientation of the magneticcapsule and external magnetic balls in an alternative process to changea magnetic capsule through the adjustment in the external magneticsystem;

FIGS. 21-24 are schematic illustration of how to rotate a magneticcapsule in xz plane;

FIG. 25 is a top view of a schematic illustration of how to rotate amagnetic capsule in xy plane;

FIG. 26 shows a side view of a schematic diagram to how to spin amagnetic capsule in xy plane;

FIGS. 27 and 28 show side views of a schematic diagram to illustrate howto adjust the position of the magnetic balls to move the magneticcapsule vertically; and

FIG. 29 is a process flow diagram to show how the system is used.

DETAILED DESCRIPTION OF SELECTED EXAMPLES

Hereinafter, selected examples of a method of how to use a magneticcapsule device to be placed in a target location and system to use inorder to accomplish the intended method steps to be described in detailwith reference to the accompanying drawings. For simplicity purpose, themagnetic capsule is explained in the context of biomedical applications,i.e. the target location is an in vivo location, for example a locationinside a digestive tract. For simplicity purpose, the medical devicedisclosed herein is designed to be placed in vivo. One of thenon-invasive methods of delivery is by swallow into a digestive tract.Therefore, the medical device disclosed herein is referred as a capsule,which should not be construed as a limitation for its shape, dimensionor size. The capsule device disclosed herein and methods of using thesame can be implemented for many other applications beyond biomedicalapplications.

The system disclosed herein is for illustration purpose only, and shouldnot be construed as limitations for what can and cannot be included insuch a system. For the method disclosed herein to be accomplished, thesystem must include two primary magnetic generation means. In the methodembodiments described below, the primary magnetic generation means arereferred as magnetic balls. The two magnetic balls are illustrated asthe same in size and magnetic strength. But this description of the twomagnetic balls is only for simplification purposes. The method stepsdisclosed herein can be used any other two magnetic generation means,with a wide variety of relative size and weight and magnetic strengthrelationships. The two primary magnetic generations in the Figureillustrations are shown as arranged on opposites of a patient,specifically on top and bottom of the patient. These relative positionarrangements between the patient and two magnetic balls should beconstrued as any limitations either. The two magnetic balls and patientcan be arranged in accordance with its intended purposes, convenienceand comfort to the patient, as long as the basic physical principles ofthe present invention is still withhold, then the method steps in thepresent invention are applicable to such a system.

The magnetic capsule, according to FIG. 8, having a length, which is thelongest dimension of the magnetic capsule. The length direction isreferred as a longitude direction of the magnetic capsule. The magneticcapsule does not have to be the cylinder shape having one or two halfdomed ends as shown in FIG. 8. The capsule can be of any shape andweight as long as the fundamental physical principal is applicable tothe magnetic capsule.

In a preferred example of the present invention, when the magneticcapsule moves linearly, the movement direction is the same as, coincide,or parallel as the longitude direction of the magnetic capsule. Themagnetic capsule moves forward means the magnetic capsule moves havingits front end pointing to the movement direction. The magnetic capsulemoves backward means the magnetic capsule moves having its front endpointing to the opposite of the movement direction. The front end, inone preferred example, comprising a diagnostic means or therapeuticmeans, such as a camera. The back end, which is defined as linearlyopposite to the front end, can also include a complimentary diagnosticmeans or therapeutic means in some examples. The magnetic capsulefurther has a magnetic dipole direction, which is parallel to thecapsule longitude, either forward or backward.

In the scope of the present invention, M is a label for magnetic momentof the external magnetic generation means, which is the externalmagnetic ball; m is the magnetic moment of the magnet inside capsule.Generally, magnetic moment M for the magnetic balls is about 25-25000A/cm², and magnetic moment m for the magnetic balls is about 0.02-2A/cm².

In one example, the magnetic moment M for the magnetic balls is about2000-3000 A/cm². In another example, the magnetic moment m for themagnetic balls is about 0.2 cm².

In the scope of the present invention, the external magnetic ball has adiameter of 8-10 cm, a minimum movement pathway is 30 cm in width, 30 cmin length and 20 cm in height; a maximum movement pathway is 60 cm inwidth, 100 cm in length and 50 cm in height; a preferred movementpathway is 40 cm in width, 60 cm in length and 30 cm in height.

In a first aspect of the present invention, the method disclosed hereinis to the magnetic capsule can be introduced to a target location byusing two external magnetic balls together, and the magnetic capsule iscapable to be suspended with or without an additional support and/orform a physical contact with another a surface. Said surface includes,are not limited to an interior wall of a colon or a stomach, positionedon top of the magnetic capsule to allow the magnetic capsule to hangfrom; an interior wall of a colon or a stomach, positioned under themagnetic capsule to allow the magnetic capsule to stand on top of it; aliquid and an interface to allow the magnetic capsule to float therein.The magnetic capsule under the influence of the combined externalmagnetic filed generated by the two external magnetic balls, can besuspended in any media in the target examination area in any relativepositions in order to accomplish its examination purpose.

The method steps include:

preparing a patient in an examination area, when capsule is inside thepatient;

bringing two magnetic balls to the examination area;

positioning the two magnetic balls so that a distance the centers of thetwo magnetic balls are more than 50 cm in the vertical direction;

suspending the magnetic capsule in a media in a target area inside thepatient, without forming any contact of an interior wall of the targetarea, wherein the media is air or CO₂;

measuring the resulted combined magnetic field by magnetic sensorsinside the capsules;

calculating a position and orientation of the magnetic capsule by twothree dimensional magnetic sensors and one three-dimensionalacceleration sensor inside the capsules, the position and orientation ofthe capsule;

adjusting the vertical and horizontal position of the two magnetic ballsso that the capsule is in a middle position of two magnetic balls.

In a second aspect of the present invention, the method disclosed hereinis directed to allow a magnetic capsule, placed in a remote target area,to be moved linearly, including both horizontally.

Referring to FIGS. 10 and 11, the magnetic capsule provided herein aremagnetic capsule endoscopes having imaging means such as a camera. Thecamera, in according to the convention of the art in the capsuleendoscope, is positioned at the front end of the capsule if there isonly one camera present in the capsule endoscope. In the schematicillustration of FIG. 10, the capsule endoscope has a camera on theright. The right end is the front end of the magnetic capsule endoscopeand left end is the rear end of the magnetic capsule endoscope. Themagnetic capsule endoscope has a magnetic dipole direction from left toright, i.e. from rear end of the capsule to the front end of thecapsule, along its longitude direction. The indented movement directionis from the left to the right, moving forward. The combined externalmagnetic field generated is configured to move the capsule in itsforward movement direction.

In this illustration in FIG. 10, the movement path is hypotheticallydesigned to be along a central line across the capsule from the rear endto the front end, which is further extended forwardly to become a centerdividing line between the two external magnetic balls. The two externalmagnetic balls are positioned on two opposing sides of the centerdividing line. The center dividing line also set up as a movementboundary for the two external magnetic balls.

In FIG. 10, the two external magnetic balls are positioned in theexamination area, one magnetic ball is positioned above the centerdividing line, and the other is positioned below the center dividingline. Because in this example, the two magnetic balls having the samemagnetic dipole and same size, therefore initially the two magneticballs are positioned at equal distance away from the center dividingline. The distance is labeled as h in FIG. 10. Each of the magneticballs has only one magnetic center. The magnetic centers of the twomagnetic balls are aligned vertically and at the same time the magneticdipole directions of the two magnetic balls are pointing to differentdirections. In FIG. 10, the magnetic ball above the center dividing linepoints up whereas the magnetic ball below the center dividing linepoints down. The two magnetic balls are positioned literally as a mirrorimage to each other across the center dividing line. The projection ofthe two magnetic centers of the two magnetic balls is ahead of themagnetic capsule in its movement direction. The distance between theprojection and the center of the magnetic capsule is labeled as x. Bypositioning the upper and lower magnetic balls in this manner, themagnetic capsule moves forward toward the projection point under thecombined magnetic field B, and applied the force F. Herein B is a vectorand has a direction from left to right, which is the same as themovement direction. The force experienced by the magnetic capsule is a“drag forward.”

Whereas, in FIG. 11, the magnetic capsule endoscope has a camera on theleft. The left end is the front end of the magnetic capsule endoscopeand the right end is the rear end of the magnetic capsule endoscope. Themagnetic capsule endoscope has a magnetic dipole direction from right toleft, i.e. from rear end of the capsule to the front end of the capsule,along its longitude direction. The indented movement direction is fromthe left to the right, moving backwards as to the magnetic capsule. Thecombined external magnetic field generated is configured to pull or dragthe capsule in its backward movement direction.

In the illustration in FIG. 11, the movement path is also hypotheticallydesigned to be along a central line across the capsule from the rear endto the front end, which is further extended forwardly to become a centerdividing line between the two external magnetic balls. The two externalmagnetic balls are again positioned on two opposing sides of the centerdividing line. The center dividing line also set up as a movementboundary for the two external magnetic balls.

Similarly, after the two external magnetic balls are positioned in theexamination area, one magnetic ball is placed above the center dividingline, and the other is placed below the center dividing line. In thisexample, if the two magnetic balls are having the same magnetic dipoleand same size, then initially the two magnetic balls are positioned atan equal distance away from the center dividing line. The distance islabeled as h in FIG. 11. If the two magnetic balls are having differentsize or at have different magnetic dipole, then difference between thetwo will be calculated and translated into differences in initialdistance, as the goal of the present method is to provide an equal andharmonized magnetic field around the capsule in opposing directions sothat the capsule can be moved in a tranquil stable manner. Each of themagnetic balls has only one magnetic center. The magnetic centers of thetwo magnetic balls are aligned vertically and at the same time themagnetic dipole directions of the two magnetic balls are pointing todifferent directions. In FIG. 11, the magnetic ball above the centerdividing line points down, towards the center dividing line whereas themagnetic ball below the center dividing line points up, towards thecenter dividing line. The two magnetic balls are positioned literally asa mirror image to each other across the center dividing line. Theprojection of the two magnetic centers of the two magnetic balls isahead of the magnetic capsule in its movement direction. The distancebetween the projection and the center of the magnetic capsule is labeledas x. By positioning the upper and lower magnetic balls in this manner,the magnetic capsule moves forward toward the projection point under thecombined magnetic field B, and applied the force F. Herein B is a vectorand has a direction from left to right, which is the same as themovement direction. The force experienced by the magnetic capsule is a“drag backward.”

In a second aspect of the present invention, the method is directed tomove the magnetic capsule endoscope horizontally forwardly or backwardlyalong the longitude direction of the magnetic capsule endoscope, bymoving the two external magnetic balls horizontally, wherein themagnetization direction of magnetic capsule endoscope, the combinedmagnetic field (B) direction and direction of the force (F) received bythe magnetic capsule endoscope are all parallel to one another. Theintended movement direction of the magnetic capsule points toward theconnecting line between the two centers of the two external magneticballs. In a preferred embodiment, a maximum point of the combinedmagnetic field (B) and a maximum point of the force (F) received by themagnetic capsule are in very close proximity to teach other.

FIGS. 10 and 11 show two examples of linear movement embodimentaccording to the aspects of the present invention. In this method, thetwo magnetic balls are vertically aligned on opposing areas where thecenter dividing line serves as a boundary. The center dividing line isalso a proposed movement direction of the magnetic capsule. Themagnetization directions of the two external magnetic balls areperpendicular to the center dividing line and opposite to each other,either both pointing to the center dividing line at the same time orpointing away from the center dividing line at the same time. Themagnetic capsule endoscope is positioned having its longitude directionalong the center dividing line. And it is required that themagnetization direction of the magnetic capsule lays horizontally alongits long its length. The force F and magnetic field B received by themagnetic capsule are normalized by their maximum value. The distancefrom each center of the magnetic ball to the center dividing line islabeled as h. Distance from the magnetic center of the magnetic capsuleto the projection line, connecting to the two magnetic centers of theexternal magnetic ball, is distance x. And distance x can be normalizedby distance h.

$\begin{matrix}{F = {\frac{\mu_{0}}{4\pi}\frac{18\mspace{11mu}{Mmhx}^{2}}{\left( {x^{2} + h^{2}} \right)^{7/2}}}} & {{Equation}\mspace{14mu} 1} \\{B = {\frac{\mu_{0}}{4\pi}\frac{6\mspace{11mu}{Mhx}}{\left( {x^{2} + h^{2}} \right)^{5/2}}}} & {{Equation}\mspace{14mu} 2} \\{{{F_{\max} = {\frac{\mu_{0}}{4\pi}\frac{2.2\mspace{11mu}{Mm}}{h^{4}}}},{when}}{{x = {0.63\mspace{14mu} h}},{B = {\frac{\mu_{0}}{4\pi}\frac{1.64\mspace{14mu} M}{h^{3}}}}}} & {{Equation}\mspace{14mu} 3} \\{{{B_{\max} = {\frac{\mu_{0}}{4\pi}\frac{1.7\mspace{11mu} M}{h^{3}}}},{when}}\text{}{x = {0.5\mspace{14mu} h}}} & {{Equation}\mspace{14mu} 4}\end{matrix}$

The relationship between distance x, distance h, and force F andcombined magnetic field B can be represented by the Equations 1 and 2,wherein M is magnetic moment of magnetic ball, m is the magnetic momentof the magnet inside capsule, u₀ is vacuum magnetic permeability.

The maximum value of F_(max) and B_(max) can also be calculatedaccording to Equation 3 and Equation 4.

FIG. 12 shows a relationship between ratio B/B_(max) and relativedistance x/h, and a relationship between ratio F/F_(max) and relativedistance x/h. As the calculation and FIG. 12 show, an ideal movementregion to achieve most stable movement occurs when distance x is between0.5 h to 0.7 h, at that time both magnetic force (F) and magnetic fieldstrength (B) are strong. In this example, h is about 15 cm andcorresponding distance x is about 7.5-10.5 cm. In this example, M ismagnetic moment of magnetic ball, m is the magnetic moment of the magnetinside capsule, u₀ is vacuum magnetic permeability.

In accordance with the aspect of the present invention, in one example,the distance h is about 5-25 cm and distance x is about 2.5-17.5 cm. Inanother example, distance h is about 10-20 cm and distance x is about5-14 cm. In another example, distance h is about 12-17 cm and distance xis about 6-11.9 cm.

FIGS. 13-15 describe a third aspect of the present invention. Referringto FIGS. 13 and 14, the magnetic capsule is placed in a way that themovement direction is its length direction. In FIG. 13, the front end ofthe magnetic capsule in on the right, the magnetization direction of thecapsule goes from left to right. The middle line along the longitudedirection of the capsule extends to become a center dividing line of theexternal magnetic control system. The center dividing line coincideswith the proposed movement direction of the magnetic capsule. The twoexternal magnetic balls are positioned on two different sides of thecenter dividing line and their respective projection positions on thecenter dividing line are ahead of the magnetic capsule. Referring toFIG. 13, the two magnetic balls are positioned above and below thecenter dividing line, having their magnetic centers are mirror image toeach other. A projection line, connecting the centers of the twomagnetic balls, perpendicular to the center dividing line, which is alsoan extension line of the longitude of the magnetic capsule. The distancebetween the magnetic center of the capsule to the projection line, orthe cross point between the projection line and center dividing line isx. The distance between the center (magnetic center) of the externalmagnetic ball to the center dividing line is h. In FIG. 13, bothexternal magnetic balls are made of same material, having the samedimensions; therefore, initially both magnetic balls are positioned atthe equal distance to the center dividing line. One key differencebetween the embodiment in FIG. 13 and the embodiment in FIG. 10 is thatthe magnetic directions of the upper magnetic ball and lower magneticball are parallel to the magnetic direction of the magnetic capsule,instead of perpendicular, but having opposite directions. In FIG. 13,the magnetic direction of the magnetic capsule is from left to right,whereas the magnetic directions of the upper and lower magnetic ballsare from right to left. In the example shown in FIG. 13, the centers ofthe upper and lower magnetic balls and the magnetic center of themagnetic capsule are in the same vertical plane. The combined magneticfield B points to the movement direction, which is to the right and theforce received by the magnetic capsule also points to the forwarddirection, to the right and the magnetic capsule is dragged forward.

FIG. 14 schematically illustrates an alternative embodiment of what isdescribed in FIG. 13, wherein the magnetic capsule is dragged backwardsinstead of forward. In FIG. 14, the front end of the magnetic capsule inon the left, the magnetization direction of the capsule goes from rightto left. The middle line along the longitude direction of the capsuleextends to become a center dividing line of the external magneticcontrol system. The center dividing line coincides with the proposedmovement direction of the magnetic capsule. Similarly, the two externalmagnetic balls are positioned on two different sides of the centerdividing line and their respective projection positions on the centerdividing line are ahead of the magnetic capsule in the proposed movementpathway. Referring to FIG. 14, the two magnetic balls are positionedabove and below the center dividing line, having their magnetic centersare mirror image to each other. A projection line, connecting thecenters of the two magnetic balls, perpendicular to the center dividingline, which is also an extension line of the longitude of the magneticcapsule. The distance between the magnetic center of the capsule to theprojection line, or the cross point between the projection line andcenter dividing line is x. The distance between the center (magneticcenter) of the external magnetic ball to the center dividing line is h.In FIG. 14, both external magnetic balls are made of same material,having the same dimensions; therefore, initially both magnetic balls arepositioned at the equal distance to the center dividing line. One keydifference between the embodiment in FIG. 14 and the embodiment in FIG.11 is that the magnetic directions of the upper magnetic ball and lowermagnetic ball are parallel to the magnetic direction of the magneticcapsule, instead of perpendicular, but having opposite directions. InFIG. 14, the magnetic direction of the magnetic capsule is from right toleft, whereas the magnetic directions of the upper and lower magneticballs are from left to right. In the example shown in FIG. 14, thecenters of the upper and lower magnetic balls and the magnetic center ofthe magnetic capsule are in the same vertical plane. The combinedmagnetic field B direction is from right to left, and the force receivedby the magnetic capsule moves the magnetic capsule from left to theright, and the magnetic capsule is dragged backwardly.

A key difference between embodiments described in FIGS. 13 and 14 andembodiments described in FIGS. 10 and 11, are the magnetic directions ofthe two external magnetic balls. In the embodiments illustrated in FIGS.10 and 11, the magnetic balls having a magnetic direction perpendicularto the magnetic direction of the magnetic capsule, whereas in theembodiments illustrated in FIGS. 13 and 14, the magnetic balls having amagnetic direction parallel to the magnetic direction of the magneticcapsule. Both embodiments can provide a horizontal stable movement tothe magnetic capsule, however the max force (F) experienced by themagnetic capsule in FIGS. 13 and 14 are about half of the max force (F)experienced by same magnetic capsule in FIGS. 10 and 11.

In the third aspect of the present invention, the method is directed tomove the magnetic capsule endoscope horizontally, forwardly orbackwardly along the longitude direction of the magnetic capsuleendoscope, by moving the two external magnetic balls horizontally,wherein the magnetization direction of magnetic capsule endoscope, thecombined magnetic field (B) direction and direction of the force (F)received by the magnetic capsule endoscope are all parallel to oneanother, but the intended movement direction is parallel tomagnetization directions of the two external magnetic balls. In general,magnetic field generated by the external magnetic ball is distributed inthree dimensions, the magnetic fields from the two external magneticballs are combined to form a combined external control magnetic field.Theoretically, there is no space limitation of the magnetic field, butit will be decayed in the inverse power of 3. Therefore, in a preferredembodiment, the two external magnetic balls present in the same verticalplane with the magnetic capsule to ensure most optimal performance.

$\begin{matrix}{F = {\frac{\mu_{0}}{4\pi}\frac{6\mspace{14mu}{{Mm}\left( {h/x} \right)}\left( {1 - {3\left( {x/h} \right)^{2}}} \right)}{{h^{4}\left( {1 + \left( {x/h} \right)^{2}} \right)}^{7/2}}}} & {{Equation}\mspace{14mu} 5} \\{B = {\frac{\mu_{0}}{4\pi}\frac{2\mspace{11mu}{M\left( {1 - {2{x/h}}} \right)}}{\left( {1 + \left( {x/h} \right)^{2}} \right)^{2}}}} & {{Equation}\mspace{14mu} 6} \\{{{F_{\max} = {\frac{\mu_{0}}{4\pi}\frac{Mm}{h^{4}}}},{when}}{{x = {0.26\mspace{14mu} h}},{B = {\frac{\mu_{0}}{4\pi}\frac{0.42\mspace{14mu} M}{h^{3}}}}}} & {{Equation}\mspace{14mu} 7} \\{{{B_{\max} = {\frac{\mu_{0}}{4\pi}\frac{2\mspace{11mu} M}{h^{4}}}},{when}}{x = 0}} & {{Equation}\mspace{14mu} 8}\end{matrix}$

The relationship between distance x, distance h, and force F andcombined magnetic field B can be represented by the Equations 5 and 6,wherein M is magnetic moment of magnetic ball, m is the magnetic momentof the magnet inside capsule, u0 is vacuum magnetic permeability.

The maximum value of F_(max) and B_(max) can also be calculatedaccording to Equations 7 and Equation 8.

FIG. 15 shows a relationship between ratio B/B_(max) and relativedistance x/h, and a relationship between ratio F/F_(max) and relativedistance x/h.

In order to make the force and magnetic field in the same direction, thecapsule magnet and two magnetic balls shall be in the same verticalplane. If it is not in the same vertical plane, there will be a force oncapsule pointing to the vertical plane besides the same direction force.

As the calculation results according to equations 5-8 and FIG. 15 firstshows, an optimal movement region to achieve strongest magnetic force(F) occurs when distance x is about 0.26 h. In this example, h isgenerally about 15 cm and corresponding distance x is about 4 cm. In theembodiments illustrated in FIGS. 13 and 14, the magnetic capsulemovement direction is x direction, up and down direction is the zdirection, the in and out of the plane direction is a y direction. Whenthe value of distance x is 4 cm, suggest that the magnetic ball movementarea in XY plane needs to be 4 cm larger than the active colonexamination area in all directions on the xy plane, including each +x,−x, +y, −y direction.

Secondly, FIG. 15 also suggests when the distance x is larger than 0.5h, the combined magnetic field will change its direction, thus thecapsule will also have to change its direction to be stable in theregion larger than 0.5 h.

FIGS. 16-17 describe a fourth aspect of the present invention, whereinthe magnetic directions of the two external magnetic balls are neitherperpendicular nor parallel to the magnetic direction of the magneticcapsule but forming a angel between 0-90 degrees. Referring to FIGS. 16and 17, for comparison purposes, with embodiments in FIGS. 10-11 and13-14, the magnetic capsule is placed in a way that is the same as thoseembodiments, that is the magnetic capsule is placed in horizontally inthe xy plane, and the movement direction is in its length direction-xdirection. In FIG. 16, the front end of the magnetic capsule is on theright, the magnetization direction of the capsule goes from left toright. The middle line along the longitude direction of the capsuleextends to become a center dividing line of the external magneticcontrol system. The center dividing line coincides with the proposedmovement direction of the magnetic capsule. The two external magneticballs are positioned on two different sides of the center dividing lineand their respective projection positions on the center dividing lineare ahead of the magnetic capsule. Referring to FIG. 16, the twomagnetic balls are positioned above and blow the center dividing line,having their magnetic centers are mirror image to each other. Aprojection line, connecting the centers of the two magnetic balls,perpendicular to the center dividing line, which is also an extensionline of the longitude of the magnetic capsule. The distance between themagnetic center of the capsule to the projection line, or the crosspoint between the projection line and center dividing line is x. Thedistance between the center (magnetic center) of the external magneticball to the center dividing line is h. In FIG. 13, both externalmagnetic balls are made of same material, having the same dimensions;therefore, initially both magnetic balls are positioned at the equaldistance to the center dividing line.

The magnetization of the external magnetic balls can be derived intoparallel and perpendicular components, then the examples and operationprinciples described in FIGS. 10-15 can be used in a combinatory manner,including parallel and perpendicular component all are in the samevertical plane.

In accordance with the aspects of the present invention, the magneticcapsule endoscope disclosed herein can not only moves horizontally in astable manner but change orientation as well. One way is to move theexternal magnetic balls in a synchronized manner along the verticaldirection (FIG. 19). Another way is to spin both magnetic ballsvertically (FIG. 20).

Referring to FIGS. 18a-b and FIG. 19, it describes that the magneticcapsule endoscope can look up and down without changing its relativeposition in the target area, that is maintaining its position in x and ydirection. In FIGS. 18a-b , the magnetic capsule start from a positionlaid horizontally on a xy plane, its length direction elongated along ax direction, whereas the two magnetic balls having a magnetic directionforming an angle between 0-90 degrees with the magnetic direction ofcapsule endoscope. The front end of the magnetic capsule is on theright. The proposed movement direction can be to the right after theorientation adjustment. As FIG. 19 shows, when both external magneticballs move vertically down along the a direction without movinghorizontally in x or y direction, the magnetic capsule will look upwhile maintaining its magnetic center at its original position in the xyplane. In the same fashion, from the original position on the left asshown in FIGS. 18a-b , if both the external magnetic moves synchronizedmatter upwardly, then the magnetic capsule will look down.

In a fifth aspect of the present invention, orientation of the magneticcapsule endoscope can be adjusted by moving both the two externalmagnetic balls along the z direction.

In one embodiment, the magnetic capsule endoscope can look up from alaid down position when both external magnetic balls along the zdirection are moved downwardly along z direction.

In an alternative embodiment, the magnetic capsule endoscope can lookdown from a laid down position when both external magnetic balls alongthe z direction are moved upwardly along the z direction.

FIGS. 18a-b and FIG. 20 describe an embodiment method that theorientation of the magnetic capsule can be changed without changing thepositions of the two external magnetic balls, specifically, thepositions of the magnetic centers remains unchanged when the front endor back end orientation of the magnetic capsule are changed. Wherein theorientation change means only just a pasture of the capsule is changed,the position of its magnetic center is not changed.

In a sixth aspect of the present invention, orientation of the magneticcapsule endoscope can be adjusted by spinning the external magneticballs simultaneously around z axis or vertical axis.

Besides moving horizontally in a stable manner, changing orientationwithout changing position, in accordance with the aspects of the presentinvention, the magnetic capsule endoscope disclosed can also rotateeither changing its position or not changing its relative position.

If the capsule is close to one magnetic sphere and far away from anothermagnetic sphere, the capsule will be largely controlled by one magneticball, either the upper one or the lower one. In this case, the capsulecontrol behavior is the same as the signal magnetic ball. It will bereduced to the patents we applied before.

In a seventh aspect of the present invention, the magnetic capsule canbe rotated in 0-90 degrees without changing its position. Before therotation, the magnetic capsule having its magnetic directionperpendicular to the center dividing line and two magnetic balls havingtheir magnetic directions forming an angle of 0-90 degrees with thecenter dividing line and during the rotation process, only the uppermagnetic ball rotate counter clockwise and the lower magnetic ball iskept still to maintain its position and orientation. In this example,one magnetic ball is the primary magnetic ball and the other magneticball is a secondary magnetic ball. The rotational magnetic filed iscontributed primary from the primary magnetic ball. In one example, themagnetic capsule is placed closer to the primary magnetic ball than tothe secondary magnetic ball. In another example, the rotation of themagnetic capsule is limited to rotate in 0-90 degrees while the back endof the magnetic capsule is anchored on either a upper interior wall orlower interior wall of the colon.

FIGS. 21-24 describe another method to rotate the magnetic capsulevertically in a xz plane. The rotation of the magnetic capsule canhappen between 0-360 degrees in either a clock wise or counter clockwisemanner. In this embodiment, FIG. 22 depicts a start position of therotation. FIGS. 22-23 shows intermediate rotation positions. As in thestart position shown in FIG. 21, the two external magnetic balls arearranged on opposing sides of a patient. A center dividing line isformed in between the two magnetic balls having a both balls arearranged at an equal distance to the center dividing line. The magneticdirection of the magnetic capsule is perpendicular to the centerdividing line. Both magnetic balls also have magnetic direction parallelto the magnetic capsule and perpendicular to the center dividing line,also the both magnetic directions are the same to the magnetic capsule.Upon turning the magnetic balls clockwise, the capsule rotate counterclock wise to the left (FIG. 22), then downwardly (FIG. 23) and to theright (FIG. 24). In all the movement sequences, both magnetic balls movesimultaneously to achieve the balanced the magnetic field for 0-360degree rotation.

In an eight aspect of the present invention, another method to rotate orvertically rotate the magnetic capsule without changing the positions ofthe magnetic capsule is disclosed, herein vertical rotation meansrotation along the xz plane. In this embodiment, the two magnetic ballmoves simultaneously and magnetic capsule rotates counter clockwise in0-360 degrees in response to a clock wise vertical rotation 0-360degrees. In a first start position, the magnetic direction of themagnetic capsule is perpendicular to the center dividing line whereasboth magnetic balls are having magnetic direction parallel to themagnetic direction of the capsule and all point to the top. In a secondstart position, the magnetic direction of the magnetic capsule isparallel to the center dividing line whereas both magnetic balls arehaving magnetic direction parallel to the magnetic direction of thecapsule, both magnetic balls point to the right whereas the magneticcapsule point to the left. In a third start position, the magneticdirection of the magnetic capsule is perpendicular to the centerdividing line whereas both magnetic balls are having magnetic directionparallel to the magnetic direction of the capsule and all pointdownwardly. In a fourth start position, the magnetic direction of themagnetic capsule is parallel to the center dividing line whereas bothmagnetic balls are having magnetic direction parallel to the magneticdirection of the capsule, the magnetic capsule points to the right andtwo magnetic ball point to the left.

FIGS. 25-26 describe a method to rotate the magnetic capsulehorizontally in a xy plane around its own magnetic center. FIG. 25 is atop view and FIG. 26 is a side view. In order to achieve a horizontalrotation along a xy plane, the magnetic capsule is laid horizontally onthe xy plane. The magnetic direction of the two external magnetic ballsare parallel to the magnetic direction of the magnetic capsule. Themagnetic directions of the two magnetic balls point to right andmagnetic capsule has a magnetic direction point to the left. Then upon asimultaneous horizontal rotation of the two external magnetic balls in acounter clockwise manner, the magnetic capsule in the xy plane willrespond with a horizontal rotation in a synchronized manner, having thesame rotation direction.

In a ninth aspect of the present invention, another method to rotate orhorizontally rotate the magnetic capsule without changing the positionsof the magnetic capsule is disclosed, herein horizontal rotation meansrotation along the xy plane. Wherein, the magnetic direction of themagnetic capsule is in the xy plane and there are opposite magneticdipole directions between the magnetic ball and the magnet inside themagnetic capsule.

In a tenth aspect of the present invention, a method to move themagnetic capsule vertically along the z direction is disclosed (FIGS. 27and 28). Wherein, the magnetic direction of the magnetic capsule isplaced perpendicular to the center dividing line. In one embodiment,moving the magnetic capsule up in a z direction is primarily byattracting the magnetic capsule upwardly by the upper magnetic ball, bythe upper magnetic ball have the same magnetic direction as the magneticcapsule. Optionally, the lower magnetic ball is moved away to reduce itsattraction to the magnetic capsule. Alternatively, or preferably, thelower magnetic ball further the lower magnetic ball further provides arepelling magnetic force by turning the magnetic direction opposite tothat of the magnetic capsule. Similarly, moving the magnetic capsuledownwardly can be accomplished by primarily attracting the magneticcapsule by the lower magnetic ball, provided that the magnetic directionof the lower magnetic ball is the same as that of the magnetic capsule.Optionally, the upper magnetic ball can be moved away to reduce itsattraction to the magnetic capsule. Alternatively, or preferably, theupper magnetic ball can be further adjusted to provide a repellingmagnetic force by turning the magnetic direction opposite to that of themagnetic capsule.

When the distance between the magnetic capsule and a first magnetic ballis three times more than the distance between the magnetic capsule and afirst magnetic ball, then the first magnetic ball is a primary magneticball and a dominate magnetic ball whereas the second magnetic ball is asecondary magnetic ball and a surrender magnetic ball, the influence ofthe surrender magnetic ball to the magnetic capsule can be ignored.Therefore, when the magnetic capsule moved closer to the primarymagnetic ball and its distance to a surrender magnetic ball is less thana third of the distance between the capsule and primary magnetic ball,then the surrender magnetic ball does not need to be adjusted in itsposition or orientation to repel the magnetic capsule.

The above-disclosed movements of the magnetic capsule are basic movementsteps. A different combination of the basic movement steps will allowcomplicated movement sequence to occur in the target area.

One exemplar system that can be used to accomplish the basic andcomplicated movement sequences is listed in FIGS. 2-7.

In the scope of the present invention, xyz coordinate system is used todefine a position or direction. FIG. 3 shows xyz axis direction withrespect to the orientation of the medical system in the scope of thepresent invention. It is for illustration purposes only. It should notbe construed as a limitation. For example, according to FIG. 3, inreferring to FIG. 2, x direction is the direction the bed moves, whichis from back to forward; y direction is the direction from onesupporting frame to another opposing supporting frame, which is fromleft to right, and z direction is the direction to move the magnetscloser and away to the patient, which is the up down direction.Horizontal rotation means a rotation around z axis, along xy plane, forexample rotation from left to right, when viewing from the front of theapparatus. Vertical rotation means a rotation around y axis, along yzplane, for example, rotation from top to bottom, when viewing from thefront of the apparatus.

ELEMENTS IN THE FIGURES ARE

-   Element 1. Motor 1-   Element 2. Z-axis upper assembly 1-   Element 3. Y-axis upper horizontal assembly-   Element 4. Motor 3-   Element 5. Magnetic ball 1-   Element 6. Right supporting frame assembly-   Element 7. Right sliding rail for the bed-   Element 8. Magnetic ball 2-   Element 9. Y-axis lower horizontal assembly-   Element 10. Motor 8-   Element 11. Z-axis uplift assembly 2-   Element 12. Motor 6-   Element 13. Base-   Element 14. Motor 2-   Element 15. Motor 4-   Element 16. Motor 5-   Element 17. Left supporting frame assembly-   Element 18. Bed-   Element 19. Left sliding rail for the bed-   Element 20. Motor 9-   Element 21. Motor 10-   Element 22. Motor 7

Details of the elements and their functions are:

-   Element 1. Motor 1:    provide power to move the upper magnetic ball up in Z direction-   Element 2. Z-axis upper assembly 1    movement control parts for the upper magnetic ball along Z-axis are    all placed on Z-axis upper assembly-   Element 3. Y-axis upper horizontal assembly    movement control parts for the upper magnetic ball along Y-axis are    all placed on Y-axis upper assembly-   Element 4. Motor 3    provide power to move the upper magnetic ball up in x direction-   Element 5. Magnetic ball 1    the magnetic ball above the bed-   Element 6. Right supporting frame assembly    supporting frame on the right and parts attached to it-   Element 7. Right sliding rail for the bed    sliding rail for the bed on the right side-   Element 8. Magnetic ball 2    the magnetic ball below the bed-   Element 9. Y-axis lower horizontal assembly    movement control parts for the lower magnetic ball along Y-axis are    all placed on Y-axis lower assembly-   Element 10. Motor 8    provide power to move the lower magnetic ball in x direction-   Element 11. Z-axis uplift assembly 2    movement control parts for the lower magnetic ball along z-axis are    all placed on z-axis lower assembly    Element 12. Motor 6-   provide power to move the lower magnetic ball in z direction-   Element 13. Base    apparatus base, placed on the ground-   Element 14. Motor 2    provide power to move the upper magnetic ball in y direction-   Element 15. Motor 4    provide power to turn the upper magnetic ball along the horizontal    plane, rotate around the z direction-   Element 16. Motor 5    provide power to turn the upper magnetic ball along the vertical    plane, rotate around the z direction-   Element 17. Left supporting frame assembly    Left apparatus supporting frame-   Element 18. Bed    Bed to provide support to a patient and carry the patient into/out    of the examination area-   Element 19. Left sliding rail for the bed    sliding rail for the bed on the left-   Element 20. Motor 9    provide power to rotate the lower magnetic ball along the vertical    plane, rotate around the z direction-   Element 21. Motor 10    provide power to rotate the lower magnetic ball along the horizontal    plane, rotate around the z direction-   Element 22. Motor 7    provide power to move the lower magnetic ball in the y direction

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to affect such feature, structure, orcharacteristic in connection with other ones of the embodiments.Furthermore, for ease of understanding, certain method procedures mayhave been delineated as separate procedures; however, these separatelydelineated procedures should not be construed as necessarily orderdependent in their performance. That is, some procedures may be able tobe performed in an alternative ordering, simultaneously, etc. Inaddition, exemplary diagrams illustrate various methods in accordancewith embodiments of the present disclosure. Such exemplary methodembodiments are described herein using and can be applied tocorresponding apparatus embodiments; however, the method embodiments arenot intended to be limited thereby.

Although few embodiments of the present invention have been illustratedand described, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the invention. The foregoing embodiments aretherefore to be considered in all respects illustrative rather thanlimiting on the invention described herein. Scope of the invention isthus indicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are intended to be embraced therein. As usedin this disclosure, the term “preferably” is non-exclusive and means“preferably, but not limited to.” Terms in the claims should be giventheir broadest interpretation consistent with the general inventiveconcept as set forth in this description. For example, the terms“coupled” and “connect” (and derivations thereof) are used to connoteboth direct and indirect connections/couplings. As another example,“having” and “including”, derivatives thereof and similar transitionalterms or phrases are used synonymously with “comprising” (i.e., all areconsidered “open ended” terms)—only the phrases “consisting of” and“consisting essentially of” should be considered as “close ended”.Claims are not intended to be interpreted under 112 sixth paragraphunless the phrase “means for” and an associated function appear in aclaim and the claim fails to recite sufficient structure to perform suchfunction.

The invention claimed is:
 1. A method to navigate a magnetic capsule,comprises introducing the magnetic capsule into a target area, saidmagnetic capsule has a longitude direction and the magnetic dipoleplaced inside the magnetic capsule has a magnetization directioncoincide with the longitude direction of the magnetic capsule; placingthe magnetic capsule in a first orientation, including its magneticdirection in a z direction; providing an external magnetic controlsystem comprising two magnetic balls, placed on opposing sides of thetarget area; and rotating the magnetic capsule in the target area toadopt a second orientation while maintaining its position in xyzcoordinates.
 2. The method of claim 1, wherein the two magnetic ballsare upper and lower magnetic balls.
 3. The method of claim 2, wherein inthe first orientation of the magnetic capsule, the two magnetic ballhaving a magnetic direction mirror to image to each other across acenter dividing line between them, the magnetic directions of the twomagnetic balls form an angle at 0-90 degrees between the center dividingline.
 4. The method of claim 3, further comprising turning the uppermagnetic ball counter clockwise while maintaining its position; andkeeping the position and orientation of the bottom magnetic ballunchanged.
 5. The method of claim 3, further comprising turning bothmagnetic balls 0-360 degrees, simultaneously in a clockwise manner alongxz plane.
 6. The method of claim 2, wherein in the first orientation ofthe magnetic capsule, the two magnetic ball having a magnetic directionparallel to each other and point to the same direction.
 7. The method ofclaim 6, wherein the second orientation differs in 0-90 degrees from thefirst orientation in a counter clock wise direction.
 8. The method ofclaim 6, wherein the second orientation differs in 0-360 degrees fromthe first orientation in a clockwise direction.